BOSTON – The first win wasn’t a fluke, and UFC lightweight champion Frankie Edgar couldn’t make it any clearer.

In a rematch that played out much like their first meeting – a UFC 112 fight in which Penn lost his belt – Edgar outclassed the once-dominant champ using a stick-and-move game plan and frequent takedowns to earn a lopsided unanimous-decision victory.

The title fight headlined Saturday’s UFC 118 pay-per-view event, which took at Boston’s TD Garden as part of the UFC’s Massachusetts debut.

Despite winning their first meeting, Edgar nonetheless entered the UFC 118 rematch as an underdog. Oddsmakers, in fact, gave him less than a one-in-three chance of pulling off a second victory.

Undaunted by the doubters, Edgar picked up where he left off in April and continued battering the Hawaiian with strikes from all angles. He really set the tone early, though, with a cage-rattling slam-takedown. Fearing additional trips to the mat, Penn became a bit flatfooted, and Edgar moved in and out with punches and kicks from all angles.

Penn finally scored his own takedown in the fourth round and quickly worked for the mount position. But despite being literally inches away from the dominant and much-needed ground position, Edgar turned his hips and then over-powered Penn to get back to his feet. Once there, the punches continued, and the champ locked up a 4-0 lead when he checked a high kick and swept Penn’s other leg out from under him.

Penn returned to his corner before the fifth and final round, and by then, his team had little to offer in the way of advice. The former champ appeared frustrated, even a bit dejected. In a last-ditch effort, Penn immediately shot for a takedown and actually took Edgar’s back while crashing to the mat. But the champ took all the wind out of Penn’s sails when he again muscled his way back to the standing position. Bur rather than sit back and relax with his comfortable lead, Edgar continued attacking with the ever-effective stick-and-move striking.

Ultimately, the judges gave him the shutout victory, and Edgar won the fight via scores of 50-45 on all three cards.

“B.J. really brought the best out in me,” said Edgar, who now can stake claim to the world’s No. 1 lightweight ranking. “I knew he was going to come in tough again. It was close the first time, and I just wanted to make a point.”

Penn had no answer during or after the fight.

“Frankie fought a great fight,” said Penn, who’s unsure if he’ll remain at lightweight or try his luck at 170 pounds. “He fought me twice, and he walked away with a decision twice. What can I say?”

Penn (15-7-1 MMA, 11-7-1 UFC) suffers back-to-back losses for just the second time in his career. Edgar improves to 13-1 (8-1 in the UFC), and thanks to an earlier bout now knows his next challenger.

Meanwhile, in the night’s co-main event, one has to give props to James Toney for getting in the cage when so few other boxers will. Otherwise, there was little to celebrate about the 42-year-old’s MMA debut.

UFC Hall of Famer (and unofficial MMA ambassador) Randy Couture didn’t eat a single punch in the heavyweight bout before he scored a takedown, quickly hopped into the mount position, and then unloaded dozens of punches en route to securing an eventual fight-ending arm-triangle choke a little more than three minutes into the first round.

Toney was simply a fish out of water once he was put on his back. Clearly confused as to how to defend against Couture’s attacks, Toney simply went along for the ride. Couture twice reset the choke attempt, but Toney was clueless as to how to defend himself. Finally, bordering on unconsciousness, Toney ultimately tapped out at the 3:19 mark of the opening round.

“I worked on that arm-triangle choke for more than a year,” said Couture, who now owns the biggest “MMA vs. boxing” victory in the short history of head-to-head competition between the two combat sports. “It was nice to finally get it.”

While no doubt a win for MMA, the 47-year-old Couture admitted that Toney had a tall order ahead of him.

“I think realistically even if he were training for nine months, that’s a lot of stuff you have to pick up in a short matter of time,” he said. “I give him credit for getting in here.”

Despite Couture telegraphing the takedown attempt and shooting from a distance, Toney simply was too slow to respond.

“He just caught me,” the boxer said. “He got me on the ground, and I couldn’t get back up.”

Although the win came against a clearly over-matched opponent and in a higher weight class, Couture (19-10 MMA, 16-7 UFC) nonetheless has moved closer to a potential light-heavyweight title shot with his third consecutive win.

Toney (0-1 MMA, 0-1 UFC), who posted a solid 72-6-3 record during his 22-year pro boxing career, hasn’t ruled out a return to MMA. But he’ll need some serious work on his ground game before he poses much of a threat to anyone in the UFC’s heavyweight division.

Maia proved too polished for Miranda, who spent most of the fight on his back and defending against submission attempts. And though his performance proved dominant (Maia earned the win via scores of 30-27 on all three judges’ cards), it was far from a crowd-pleaser and booed by most of the TD Garden crowd.

Maia (13-2 MMA, 7-2 UFC), though, was fighting for the first time since his disappointing loss to champ Anderson Silva in April. For the middleweight contender, who wants a second shot at the belt, the win was more important than the manner in which it came.

Miranda (12-2 MMA, 1-2 UFC), meanwhile, has lost two of three since joining the UFC on the heels of a perfect 11-0 run.

In a No. 1 contender’s bout, lightweight Gray Maynard earned a shot at the title – but he did little to change his reputation as a lay-and-pray wrestler without finishing ability.

The former state Michigan State University wrestler used frequent takedowns and a smothering top game to earn a unanimous-decision victory over perpetual contender and Boston-based fighter Kenny Florian.

Florian attempted to keep the fight standing, where he had his best shot at victory. But Maynard’s relentless attacks left Florian clearly frustrated as he was taken to the mat again and again. A late string of submission attempts fell short, and Florian was denied his third shot at a UFC belt.

Instead, Maynard earned the unanimous-decision victory (30-27, 30-27, 29-28) and went the distance for the seventh consecutive time.

“I finally get to the spot where I get a chance at the belt,” Maynard said. “Love me or hate me, I come out and win.”

Back in January, Maynard was expected to get a title shot, but a lackluster split-decision win over Nate Diaz at UFC Fight Night 20 instead opened the door for Frankie Edgar. But with his eighth straight win in the octagon, Maynard (10-0 MMA, 8-0 UFC) is going to be difficult to pass over gain.

Florian, meanwhile, falls to 14-5 (11-4 UFC) and halts the momentum he built from recent back-to-back wins over Clay Guida and Takanori Gomi.

In the night’s first PPV bout, welterweight Marcus Davis was cut early above the right eye with a slicing left hook and spent three rounds trying to fight a game Nate Diaz with his one good eye.

Against a well-rounded fighter who a significant reach advantage, it was simply too much for the former boxer.

Davis, who boxed in and around Boston during his former career, continually wiped away blood as Diaz used a traditional game plan with a steady stream of strikes. “The Irish Hand Grenade” kept things even through two rounds. But by the third, with his eye blown up from a hematoma and bleeding profusely, Davis probably couldn’t even see Diaz’s final takedown.

Davis tried to escape once on the mat, but Diaz quickly slapped on a tight guillotine choke. Referee Yves Lavigne halted the bout at the 4:02 mark of the final frame with Davis clearly out cold.

Diaz, who picked up his second win since a move up from lightweight, isn’t sure he’ll stay at 170 pounds.

“I don’t know,” said the “TUF 5″ champ, who complained of a likely broken hand suffered in the second round. “I want to go back (to lightweight). There’s a lot of tough guys at 155 – Gray Maynard and all those hotshots.”

Diaz (13-5 MMA, 8-3 UFC) now has won three of his past four fights, and the lone loss came via close split decision to Maynard back in January. Davis (17-7 MMA, 9-5 UFC), meanwhile, now has lost three of his past four.

As the UFC 189 tour made its last stop in Dublin, featherweight champ Jose Aldo was met with a torrent of abuse from the Irish fans. It might have been unpleasant, but it might also have been just what he needed.